Transfer mechanism



L. J. PIANOWSKI TRANSFER MECHANISM March '3, 1964 10 Sheets-Sheet 1 Filed Jan. 7, 1959 llllllllll l March 3, 1964 L. J; PIANOWSKI v TRANSFER MECHANISM 10 Sheets-Sheet 2 Filed Jan. 7, 1959 March 3, 1964 J. PIANOWSKI TRANSFER MECHANISM 10 Sheets-Sheet 5 Filed Jan. 7, 1959 M1 H| n |n |u- 4 mm 3 V m a r w; y M a v J F a a w L y 5 I. 1| Illll Ki i HHHHHHHHHMH u u U fl Mar 1964 L. J. PIANOWSKI TRANSFER MECHANISM l0 Sheets-Sheet 4 Filed Jan. 7, 1959 1 4 1 fi )7 w ME I I I I J a I W a M y j Mm M E I Iv V w .H I I I I INH IHHU m m d ||.I| w I a l z 1NVENTOR. I A807? J, fzdflazoasiz,

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March -3, 1964 J. PIANOWSKI 3,123,197

TRANSFER MECHANISM Filed Jan. 7, 1959 10 Sheets-Sheet 5 IN V EN TOR.

Fur/ 1 10072 J z avazlAs F z' March 3, 1964 .J. PIANOWSKI TRANSFER MECHANISM l0 Sheets-Sheet 6 Filed Jan. '7, 1959 INVEN TOR A6077 .Ifzlarrawsiz'.

March 3, 1964 L. J. PIANQWSKI TRANSFER MECHANISM 10 Sheets-Sheet '7 Filed Jan. 7, 1959 March 3, 1964 L. J. PIANOWSKI 3,123,197

TRANSFER MECHANISM Filed Jan. 7, 1959 10 Sheets-Sheet 8 March 1964 .L. J. PIANOWSKI 3, 7

- TRANSFER MECHANISM Filed Jan. 7, 1959 1O Sheets-Sheet 9 I INVENTGR. #607? JC fizzrau/sfzl Mam}! 1964 J. PIANOWSKI TRANSFER MECHANISM l0 Sheets-Sheet 10 Filed Jan. 7, 1959 INVENTOR. lea?! J7 z'dzr'aa sA i BY United States Patent 3,123,197 TRANSFER MECHANISM Leon 5. Pianowslri, Detroit, Mich, assignor to The Udyiite @orporation, Detroit, Mich, a corporation of Delaware Filed Ian. 7, 195$, Ser. No. 785,479 7 Claims. (El. 198-l9) The present invention relates to an improved transfer mechanism of the type used to transfer article carrying racks from one conveyor to another. More particularly, the present invention contemplates the provision of an improved transfer mechanism for use in automatically transferring such racks between intermittently moving conveyors or intermittently moving portions of conveyors.

While transfer mechanisms of this type have a wide variety of applications, the preferred embodiment illustrated and described herein illustrates the use of the improvements of the present invention in a transfer mechanism for transferring racks carrying articles to be electroplated, from an intermittently moving shop conveyor or portion thereof, while it is stopped, to an automatic plating machine, and transferring racks carrying processed, or plated articles, from the plating machine to the shop conveyor.

It is an object of the present invention to provide an improved transfer mechanism of the above mentioned type, which is simple in design, easily manufactured, durable in construction, and reliable and efficient in operation.

It is an object of the present invention to provide an improved transfer mechanism for transferring work carrying racks between first and second conveyors and in which a cart shuttles back and forth between the conveyors and is provided with rack supporting means which moves vertically only, relative to the cart, the latter being provided with guide means which prevents horizontal movement of the rack supporting means relative to the cart.

It is also an object of the present invention to provide an improved transfer mechanism of the above mentioned type which includes means providing delay safety positions and means successively moving a cart to transfer stations at each of the conveyors and then stopping it in a delay safety position intermediate the conveyors.

Another object of the present invention is to provide an improved transfer mechanism of the above mentioned type including a cart movable between a transfer station of the first conveyor and a transfer station of the second conveyor, and which includes a rack support which is adapted to carry a rack during movement of the cart in one direction between said stations and wihch includes means for gradually moving the rack support vertically in one direction during such rack carrying movement of the cart.

It is also an object of the invention to provide an improved transfer mechanism of the above mentioned type including a cart having a vertically movable rack support and rack support positioning means which is movable while the cart is in one of said stations to move the rack support vertically in one direction and which is movable while the cart is in the other station so that during movement of the cart from the unloading station to .the loading station, the rack support is gradually moved vertically in the opposite direction.

A further object is to provide an improved transfer mechanism which provides vertical movement of the rack support for transferring of a rack between one conveyor and the transfer mechanism, butin which the transfer mechanism does not provide any substantial vertical movement of the rack support while the cart is at the other conveyor, the transfer between such other conveyor and the transfer mechanism being in response to vertical movement of a part of such other conveyor.

3323,19? Patented Mar. 3, 19%4 It is also an object of this invention to provide an improved transfer mechanism for automatically transferring art1cle carrying racks from a first conveyor to a loading station of a second conveyor and simultaneously transferring article cairying racks from an unloading station of the second conveyor to the first conveyor.

Another object of the present invention is to provide an improved transfer mechanism for transferring work carrying racks between two spaced conveyors and which is powered by a simple single power means, which both moves a cart between transfer stations at the conveyors, and vertically moves rack supporting means carried by the cart reaching a transfer station.

More specifically, it is an object of the present invention to provide such a transfer mechanism which employs a sirnple mechanical drive which, without the operation of limit switches or valves, vertically moves the rack supporting means as soon as the cart reaches a transfer station and effects a transfer of a rack between the cart and one of the conveyors.

It is a further object to provide such a transfer mechanism which includes a chain and sprocket type drive mechanism in which a bracket connected to the chain drives the cartbetween transfer stations and passes around a sprocket wheel when the cart reaches a transfer station to effect vertical movement of the rack supporting means relative to the cart.

It is a further object to provide an improved transfer mechanism of the above mentioned type of a design such that the proportions thereof may be readily varied to pro vide desired variations in the path of travel of the rack supporting means.

It is also an object to provide such a construction in which the vertical load carried by the rack supporting means is separately taken and not transferred to the chain.

Other and more detailed objects of the present invention will be appreciated by those skilled in the art from a consideration of the following specification, the appended claims and the accompanying drawings wherein:

FIGURE 1 is a broken plan View illustrating partially diagrammatically a transfer mechanism embodying the present invention disposed for effecting transfers between a shop conveyor and an automatic plating machine;

FIGURE 2 is a sectional view of the structure illustrated in FIGURE 1, taken substantially along the line 2-2 thereof, but showing the position of the transfer mechanism just prior to the lowering of the rack onto the shop conveyor hook;

FIGURE 3 is an enlarged view similar to FIGURE 2 showing the position of the transfer mechanism after the transfer of a rack to the shop conveyor;

FIGURE 4 is an enlarged broken elevational view of the structure illustrated in FIGURE 1, taken substantially from the line 44 thereof;

FIGURES 5 and 6 are broken enlarged sectional views of the structure illustrated in FIGURE 3, taken substantially along the lines 5-5 and 66 thereof, respectively;

FIGURE 7 is a diagrammatic view showing the limit switch arrangement for the transfer mechanism illustrated in FIGURES l to 6 inclusive;

FIGURE 8 is a broken plan view similar to FIGURE 1 showing a transfer mechanism constructed according to a modified form of the invention;

FIGURE 9 is a broken side elevational view of the transfer mechanism illustrated in FIGURE 8;

FIGURE 10 is a broken plan view of the construction illustrated in FIGURE 9;

FIGURE ll is a broken enlarged sectional view of the structure illustrated in FIGURE 9, taken substantially along the line 11-41 thereof;

FIGURE 12 is a broken enlarged end elevational View u! of the structure illustrated in FIGURE 9, as seen from the right-hand end thereof;

FIGURE 13 is a broken enlarged somewhat diagrammatic view showing certain details of the structure illustrated in FlGURE 9;

FlGURE l4'is a diagrammatic view showing alternative part positions and the resulting effect upon the path of movement of'the rack support;

FIGURE l5 is a family of curves showing various paths Of movement of the rack support which may be selectively incorporated in the transfer mechanism; and,

FIGURE 16 is a broken end elevational view similar to FlGURE 12, showing a transfer mechanism embodying another modified form of the invention. 7

Referring to the drawings, and particularly to FIG- URES 1 to 6 thereof, the transfer mechanism of the present invention is generally indicated at 2t) and in the application thereof there illustrated, is employed to transfer work supporting rack 22 between a shop conveyor 24 and the conveyor 26 of an automatic electroplating machine 28. In the particular machine illustrated in FIG- URES l, 2 and 3, the machine conveyor 26 is carried by a machine chassis 30 which moves between a lower position illustrated in full lines in FIGURE 2, and a raised position illustrated in broken lines in FIGURE 2, and the machine 28 has at one side tiereof a space between tanks 32 and 34 thereof providing a loading station 36 and an unloading station 3d. The shop conveyor 24 has corresponding stations designated unloading station 46 and loading station 42. In the transfer mechanism Zll of FIG- URES 1 to 6, inclusive, there are two substantially identical units 44 and 46, the unit 44 constituting a loader which is here so designated because it loads the plating machine 28, and the unit 46 constituting an unloader for the machine 28. These units are interconnected and held in spaced parallel relation by a spacer frame 48 and are disposed with the loader 44 extending between the unloading station 40 of the shop conveyor 24 and the loading station 36 of the plating machine 23, and the unloader 46 extending between the unloading station 38 of the machine 2 8 and the loading station 42 of the conveyor 24.

Because of the identity of construction of the units 44 and as, only the loader 44 will be described in detail, the corresponding parts of the unloader as being designated by the same numeral with a prime mark, where reference thereto is believed to facilitate understanding of the invention. The loader 44 comprises a fabricated base frame 5t) which is connected to the unloader base 543' by the spacer frame 43.

The loader base Eli extends from the shop conveyor unloader station 46 past the machine loading station 36 and underneath the tank at the opposite side of the machine, as best illustrated in FIGURE 1. A pair of tracks 52 are mounted on the base 5% and extend longitudinally thereof at opposite sides thereof between the conveyor unloading station and the machine loading station 36 and are supported in spaced parallel relationabove the base St? on uprights 5d interconnected by transverse braces 55. in the preferred embodiment illustrated, these tracks 52 are formed of angles 56 and 5% which define outwardly facing channels. A cart generally indicated at so is mounted on the tracks 52 for movement between the unloading station ill and the loading station 36. This cart as comprises a pair of inwardly facing channels 62 interconnected by transverse members dd and which carry, as best illustrated in FIGURE 5, rollers 6-6 adapted to roll within the outwardly facing channels of the tracks 52, the rollers 66 rolling along the horizontal flanges of the lower angles 56.

As illustrated in FIGURE 5, each roller as is carried on a bolt member 68 which extends through and is supported on a plate 70 welded across the inwardly facing channel 62. The cart 659 also includes, at opposite sides trereof, ve tically extending tubular posts '72, the lower ends of which are welded to the outer faces of the channels 62, as best illustrated in FIGURE 5 centrally thereof.

The posts '72 are additionally supported by inclined braces 74 secured at their upper ends to the posts '72 and secured at their lower ends to the channels 62. adjacent the opposite ends thereof. These braces 74 are interconnected by tubes 76 extending transversely of the cart to further support the posts 72 against movement transversely of the cart. The transverse frame member 64 at the outer or left-hand end of the cart, as viewed in FIGURE 3, carries a depending channel 7% best illustrated in FIGURE 5, braced by a gusset plate 8% and which carries at its lower end a bracket 82 to which is connected the outer end of a piston rod 84 of a hydraulic cylinder 86 which is mounted in the base 59 and disposed longitudinally and centrally thereof.

Each tubular post '72, which is secured to the cart frame as above described, carries an inner movable post 88 extending outwardly of both ends of the post 72:. At its upper end the post 88 carries a pair of angles welded thereto to provide a W-shaped rack support 94} which is adapted to receive and support a downwardly opening V-shaped arm 92 extending laterally outwardly of the rack 22. At its lower end the movable post 88, as best illustrated in FIGURE 5, carries a roller 94 supported on an angle 96 for rotation about a horizontal axis. Each roller 94 is received in a lift track 98 in the shape of an inwardly facing channel extending longitudinally of the loader below the track 52 and externally of the uprights 54 upon which it is supported. Referring to FIG- URES 6 and 3, each lift track 93 is pivotally supported at its inner or right-hand end as viewed in FIGURE 3, upon a transversely extending pivot bar ltltl (see FIG- URE 6) rotatably supported at opposite sides of the frame in bearing blocks M92. The bar 1% is connected to the lift tracks 98 by pins 1M extending through a collar 1% which is welded within the lift track 98 and receives the end of the pivot bar 169.

At its outer, or left-hand end, each lift track 98 is secured to a lift frame generally indicated at M8. The lift frame 108 comprises a transversely extending angle \llltl, the opposite ends of which are secured to the top of the lift tracks 98 at the outer or left-hand ends thereof. Adjacent its center the angle llltl has an inverted generally U-shaped frame portion 112 extending upwardly therefrom. The transversely extending angle 114 constituting the web portion of this U-shaped frame portion also serves to mount a bracket 116 providing a pivotal connection for the upper end of the piston rod 118 of a hydraulic cylinder 124), the lower end of the cylinder 12d being pivotally mounted on a transversely extending base member :122.

It will now be appreciated that when the cart is in the loading station it? of the shop conveyor 24*, movement of the lift track 98 from its lower position, which is the position in which the lift track 93 is shown in FIGURE 3, upwardly to the position in which the lift track )8 is shown in FIGURE 3, will cause the movable post 38 and hence, the W-shaped rack support 9%, at its upper end, to be raised. It will also be appreciated that the movable rack support post 83 may be gradually raised or lowered during movement of the car 6t? depending upon the position of the lift track 98 which will serve as a ramp along which the roller 94 will travel.

The shop conveyor 24 has spaced therealong a plurality of supports generally indicated at 124 whicn are movable therealong and which include a horizontally extending bar 126 adapted to engage under laterally inwardly extending inverted V-shaped support arms 128 provided on the racks 22. From the foregoing description it will be appreciated that the cart so is moved, in the construction illustrated in FIGURES l to 6, inclusive, by the supply of hydraulic pressure to the hydraulic cylinder 86, and that the lift track 93 is moved to control the position of the rack support Qtlby controlling the pressure in the hydraulic cylinder 12%. it will, of course, be appreciated that the carts 6t} and 60" must be moved in proper timed relation to the operation of the shop conveyor 24 and the conveyor 26 of the automatic plating machine 23. The shop conveyor 24 forms no part of the present invention and may be of any construction such that the supports 124 are moved to and from and stopped in the unloading and loading stations 46 and 42, respectively, of the conveyor 24.

Similarly, the automatic plating machine 28 and its conveyor 26 form no part of the present invention and may be of any construction in which the chassis 36 is moved between the positions illustrated in FIGURE 2 and in which the conveyor 2-6 is provided with rack supports 13% which are moved to and from and are stopped in the machine unloading and loading stations 38 and 36, respectively.

From the foregoing description of the construction of the improved transfer mechanism of the present invention, it will be appreciated that the operation involves the transfer of a rack 22 carrying raw or unplated work from the shop conveyor 2 to the loader cart dil at the conveyor unloading station as, movement of the cart 65 to the machine conveyor loading station 36 and the transfer at that station of the rack 22 from the cart 60 to the machine conveyor 26. During these steps in the operation another rack 22' carrying plated work is simultaneously being transferred from the machine conveyor 26 at the unloading station 38 thereof to the cart so, thence carried by the cart "60' to the loading station 42 of the shop conveyor 24 and there transferred from the cart as to the conveyor 24.

It will be appreciated that this general operation may be provided by any suitable control system, a controlling consideration being that the control of the transfer mechanism 2a is interlocked with the control of the automatic plating machine 28 and of the conveyor 24 to prevent damage to the equipment. To this end delay safety positions are provided at which the carts ea and 6%" stop until the conveyors are ready for them to effect their simultaneous loading and unloading transfers. The delay safety position of the cart '69 of the loader 44 is indicated in FIGURE 3 by the center line 132 and the delay safety position of the cart 60 of the unloader as is indicated by the center line 134. The loader cart 6% stops at the center line 132 when it is moving away from the machine conveyor 26 and the unloader cart 6% stops at the center line 134 when it is moving away from the shop conveyor 24. This may be accomplished in any suitable way as, for example, by limit switches 136 and 136 diagrammatically illustrated in FEGURE 7 which control the supply of liquid to the hydraulic cylinders as and as. When a rack support i124 of the shop conveyor reaches the unloading station it actuates a limit switch (not shown), which starts the cart so of the loader toward the unloading station As the cart as reaches unloading station 49, it actuates limit switch 138 which both stops the cart 6% by stopping the flow of liquid to cylinder 86 and supplies liquid to hydraulic cylinder 124) which raises the lift frame 1% and with it the lift track 98, the movable post 88 and the rack support 90 which lifts the rack 22 from the conveyor support 24. As the lift frame 1% reaches its upper limit of travel it actuates a limit switch 140- which starts the cart at toward the machine conveyor as and its loading station as. As the cart or, now carrying a rack 22 approaches the machine conveyor loading station 36, it may actuate a limit switch M2 causing the cart as to proceed toward loading station at a reduced speed. Upon reaching loading station as, the loader cart es is stopped by actuating limit switch 144 which also lowers the lift frame 103 and track 98 and starts the machine chassis 3t) up. The lift frame 108 is stopped at its lower limit by again actuating limit switch 14% which also starts the loader cart as toward its delay safety position 132 at which it is stopped by actuating limit switch 136.

The cart 6% of the unloader 46 is started toward the machine conveyor 26 from its delay safety position 134 when the machine conveyor 26 has completed a transfer movement of the racks along the conveyor, which it effects while the chassis 39 is in its raised position. Upon completing this upper transfer movement a limit switch (not shown) is actuated which starts the machine chassis 30 down and also starts the cart tit)" of the unloader 46 toward the machine and its unloading position 38. As the unloader cart 60' reaches this unloading position 38, it actuates a limit switch i138 which stops the cart 6t) in the unloading position 33 and raises the lift frame 108 and the lift track 98. When the lift frame 108 reaches the upper limit of its movement it actuates limit switch 149' stopping the lift frame M8 in its upper position and starting the unloa-der cart 60 toward the shop conveyor 24, provided the machine chassis has reached the lower limit of its travel and actuated a circuit preparing limit switch (not shown). This downward movement of the machine chassis 39 transfers a rack 22 of plated work from the machine conveyor 26 to the cart as. The unloader cart as then proceeds toward the shop conveyor 2d and the loading station 42 thereof and as it approaches this loading station, it may actuate a limit switch 142 causing the cart ea to proceed toward the loading station 36 at a reduced speed. Upon reaching loading station 42, the unloader cart 60 is stopped by actuating limit switch 144 which also lowers lift frame 1% to transfer the rack 22' from the cart 60" to one of the supports 12d of the conveyor 24. As the lift frame 193' reachesits lower limit, it actuates limit switch which stops it in its lower position and starts the unloader cart 6t)" toward its delay safety position 134. This actuation of the limit switch 144i also starts the conveyor 24. The unloader cart as proceeds toward and is stopped at its delay safety position 13d by actuating the limit switch 136'. The carts es and 60' remain in their respective delay safety positions 132 and 134- until they are again started toward the shop conveyor 24 and the machine conveyor as, respectively, as described above.

Any suitable electric circuit and hydraulic system may be employed for providing the above described cycle of operation of the transfer mechanism. A suitable electric circuit and hydraulicv system will be apparent to one skilled in the art and accordingly, the specific details of the electrical circuit and hydraulic system form no part of the present invention and are not included in the present disclosure.

In the embodiment of the invention illustrated in FIG- URES 1 through 7, inclusive, the transfer mechanism comprises a pair of similar units 44- and 46 which operate simultaneously, one loading the automatic plating machine 28 from the shop conveyor 24, while the other is unloading the plating machine and transferring the racks to the shop conveyor.

In a modified form of the present invention, illustrated in FIGURES 8 through 16, inclusive, the transfer mechanism which is generally indicated at 159, comprises a single unit extending between the plating machine 28 and the shop conveyor 2 which unit successively operates to load and unload the machine conveyor. In the construction illustrated in these figures, the transfer mechanism 15d, in addition to providing the vertical movement incident to unloading a raw rack from the shop conveyor and to loading a finished rack on the shop conveyor, also provides the vertical movement incident to transferring a raw rack to the machine conveyor and to transferring a finished rack from the machine conveyor. Referring to FfGURE 8, the transfer mechanism 154) extends between a transfer station 1 5 at the shop conveyor 24 and a transfer station 148 at the machine conveyor 26. The transfer mechanism comprises a main frame generally indicated at 152 consisting of longitudinally extending angles 154 supported on legs 15d and connected by transverse frame members Q58. These angles 154 carry longitudinally extending inwardly facing channel-shaped tracks 16% In this modified form of the invention the cart is generally indicated at 162 and includes a base plate 164 supported on spaced longitudinally extending angles 1-66 welded to the underside of the base plate 16 and carrying longitudinally spaced rollers 16% mounted for rotation about a horizontal axis and disposed to roll within the channel-shaped tracks 16%. At its opposite sides the cart 162 has upwardly turned tapering sides 17% which may be formed integral with the base plate 164 and whica carry centrally thereof vertically disposed hollow posts 172. welded or otherwise suitably secured thereto. Each hollow post 172 carries an inner vertically movable post 174, the upper end of which carries a laterally inwardly extending support arm i176 adapted to engage a co-operating support arm 175 onthe rack 1'77 and the lower end of which has a lift bracket 178 secured thereto by bolts 180. This lift bracket comprises a horizontally extending inwardly opening channel-shaped section 1 82 and an upwardly extending attaching portion 184 adapted to overlie and be secured by the bolts 1% to the lower end portion of the movable post 174. Each of the side plates 17th of the cart 162 also has welded thereto a pair of vertically extending parallel drive bars 186 disposed at opposite sides of the post 172. As best illustrated in FIGURES 1-1 and 12, these drive bars 186 have inwardly offset lower end portions which extend downwardly from the cart base plate 164 in spaced parallel relation. The cart 162. is driven through these bars 136 in a manner which will now be described.

A pair of parallel sprocket shafts 138 and 1% are spaced longitudinally of and extend transversely of the frame 152. These shafts 133 and 1% are journalled in bearing blocks 1% secured to the inner sides of the depending flanges of the main frame angles 15d. Outwardly of the frame channels the shaft 183 carries at each end thereof a sprocket wheel 1% keyed thereto and similarly, the shaft 1% carries sprocket wheels res. At each side of the frame 152. is a roller chain 198 trained over the sprocket wheels 194 and 1% at corresponding ends of the shafts and 15 h. The shaft 133 is driven through a sprocket wheel 2% keyed thereto between the frame angles 1574, by a chain 2% trained over the sprocket wheel 2% and over another sprocket wheel 2% keyed to the output shaft of a speed reducer 2% driven through a suitable coupling 2 5% by a hydraulic motor 21-h. Each chain 1.98 carries a drive bracket 212 secured to the chain by what is known in the trade as a K.1 attachment. In this attachment the conventional outer side plates of a roller chain are replaced by side plates 214 which have laterally outwardly turned flanges 16 for attachment purposes. As illustrated in FlGURE 11, the bracket 232 has a horizontal flange 218 which is bolted to the flanges 216 of the l -l attachment and has a vertical flange 22% at the outer sideof the chain and which carries a roller 222 mounted at the inner or lefthand side of the flange 22d as viewed in FKGURES l1 and 12, for rotation about a horizontal axis so disposed as to coincide with the axis of the shaft 188 when the portion of the chain to which the bracket 2-12. is connected, is engaging the sprocket wheel 1%. Similarly, the axis of the roller 22.2 coincides with the of the shaft 1% when the portion of the chain 1% to which the bracket 212 is attached, engages the sprocket wheel 1%. Each roller ZZZ rolls along the upper surface of a support bar 224 extending longitudinally of the main frame and supported therefrom outwardly of the. chain 1% and sprocket wheels 1194 and 1% on transversely extending angles 22a. in this manner the bracket 212 is vertically supported on the frame 152 without relying on the chain for vertical support. Stability for the bracket in the plane of the chain 1% is provided, as best illustrated in FIGURE 13, by brackets secured to adjacent links of the chain 193, also by Kl attachments. These brackets 22% each have a vertically extending flange disposed in the plane of the flange 22% of the bracket all.

and having aa arcuate edge surface 232 adapted to lit a co-operating arcuate edge surface 234 of the flange 226 of the bracket 212 when the links of the chain to which the bracket and 223 are attached, are trained over the sprocket wheel 1%.

The flange 22 of the bracket 212, at its outer or righthand side, as viewed in FIGURES 11 and 12, carries a drive disk 236 stud elded thereto as illustrated at 238 in FEGURE 11, in spaced relation to the axis of the roller 222. The drive disk 236 fits between and is adapted to engage the adjacent edges of the drive bars rat to drive the cart 162. The drive bracket 212 also carries a roller 24tlwhich, in the construction illustrated, is mounted eccentrically of the drive disk 236 on a horizontally disposed bolt 242 extending through the disk 2% and the flange 22% of the bracket 212, the roller 240 being carried by the bolt 24.2 outwardly of the drive disk 236 or to the right thereof as illustrated in FIGURES l1 and 12. The roller 2% is disposed within the inwardly facing channelshaped fitting 13?. secured to the end of the movable lift post 174.

It will now be appreciated that as the drive bracket 212.

is moved horizontally by and with the chain 1%, the drive disk 23% engages one of the drive bars 186 and moves the cart along the track 160. When the bracket Z12 reaches one of the sprocket wheels 194 or 1%, and moves around the sprocket wheel, it will be appreciated that the drive disk 236 engages the opposite drive bar 1% to stop the cart and move the cart in the opposite direction. During this movement of the bracket 212 about either of the sprocket wheels, the roller 24% co-operates with the channel-shaped fitting 182 in which it is disposed, to move the movable lift post 174 vertically. During this movement of the drive bracket 212, its supporting roller 222 remains in engagement wih the upper surface of the supporting bar 2-24 at all times.

It will be appreciated, also, that the spacing of the roller 2.46} vertically relative to the roller 222 will determine the amount of vertical movement of the lift post 15 4. Also, the vertical spacing of the disk 236 relative to the roller 222 will determine the distance which the cart 162 moves beyond the axis of the sprocket wheels 194 and 1%. Both of the factors, that is, the amount of movement of the cart beyond the axis of the sprocket wheels and the vertical movement of the lift post 1'74 co-operate to determine the path of movement of the rack supporting arm 176 at the upper end of the lift post 174.

This is clearly illustrated in FIGURE 14 in which the spacing of the roller 24% eccentrically of the sprocket wheel 194 is such as to provide the desired vertical movement of the rack support 176, the highest and lowest positions of which are there indicated at 176a and 176.), respectively. Intermediate positions of the rack support arm 1%, corresponding to the full line positions of the drive disk 236, are shown in full lines in FIGURE 14. The broken line intermediate positions of the rack support arm I'M shown in FIGURE 14 illustrate'the effect of moving the drive disk 236 from the full line position there illustrated to the broken line position there shown.

FIGURE 15 is a family of curves illustrating a number of different paths which the rack support arm 176 may be made to travel for a given spacing of the lift post driving roller Zitl relative to the roller 222 by varying the vertical spacing of the drive disk 23s relative to the roller 222. which, as previously stated, is coaxial with the sprocket wheel during movement of the drive bracket 212 about the sprocket wheel. The curve indicated by the reference character 244 is a circle and represents the path of movement which would be obtained when the drive disk 236 is coaxial with the lift post roller 24%. The inner, or left hand curve 246 indicates a path of travel which would be obtained with the drive disk 236 disposed slightly closer to the axis of the roller 222 than is the lift post roller 24%. Y

in the construction illustrated in FIG 8 through 14, inclusive, the drive disk 236 is spaced from the axis of the roller 222 a greater distance than is the roller 246} which drives the lift post 174. By varying this spacing the rack support arm 176 may be made to follow, for example, any of the paths indicated by the other curves of FIGURE 115. The transfer mechanism construction illustrated in FIGURES 8 through 13, inclusive, is designed to cause the rack support arms 17% to follow the path indicated by the curve 245 of FIGURE 15.

It will be appreciated that the spacing of the axis of the drive disk 2% from the axis of the roller 24% will determine the deceleration and acceleration of the cart 162 as the drive bracket 21?; passes around the sprocket wheel. For example, when the rack support arm 1'76 follows a path indicated by the curve 248, the cart 162, which moves at a uniform rate of speed while the drive bracket 212 is travelling between the sprocket wheels 194 and 1%, will deceleratc in the distance indicated at 250 in FiGURE 15, which is the distance between the axis of the drive disk 236 and the axis of the roller 222. As the drive bracket 212 passes around the sprocket wheel 1%, for example, while the chain is moving in the direction indicated by the arrow 252 in FIGURE 13, the cart 162 during the first 90 of rotation of the sprocket wheel 194, decelerates from the above mentioned uniform speed to a speed of Zero and during the next 90 of rotation of the sprocket wheel 194, the cart 162 accelerates in the opposite direction to the above mentioned uniform speed.

The transfer of the rack to or from the rack supporting arm 176 is made at the midpoint of the curve, or referring to FlGURE 14, when the rack support arm 176 is in the position indicated at 1760. The sprocket wheel turns at a constant angular velocity during this transfer and accordingly, it will be appreciated that the linear velocity of the rack support arm 176 is less, at the midpoint of the curve, as the distance of the drive disk 236 from the roller 222 is increased. Referring to FIGURE 9, the transfer mechanism is so constructed that the center line of the shop conveyor is tangent to the path of movement of the center of the drive disk 236 as it passes around the sprocket wheel 1%. Similarly, the center line of the machine conveyor is tan-gent to the path of movement of the center of the drive disk 236- as it passes around the sprocket wheel 1%.

At the center of the lower course of the chain 198, between the sprocke wheels 1% and 1%, is a chain support 252 which is supported on and extends between transversely extending base members 254. It will be appreciated that since the sprocket shaft 13% is the one which is driven, the lower course of the chain 193 will be slack during operation of the mechanism to move the cart 162 to the right, as vie-wed in FIGURES 7 and 8. During such operation the lower course of the chain is supported by the support 252.

The position of the fitting 132 at the lowerend of the movable lift post 174-, when the portion of the chain 19-8 to which the drive bracket 212 is connected is a part of the lower course of the chain 1%, is shown in .broken lines in FIGURE 10. At opposite sides of the base and also mounted on the transverse base members 254 at the outer ends thereof, are suitable stop bars 255 which extend longitudinally of the mechanism, as is best seen in FIGURES 7 and 8. As will be seen from the above mentioned broken line showing in FIGURE 10, these stop bars 256 are disposed inthe path of movement of the lift post fitting 182 as the drive bracket 212 moves along the lower course of the chain 1%. The stop bars 256 are employed as safety stops and are not used in normal operation, the stopping of the cart 162 being in response to the actuation of limit switches 25% and 2611 (see FI URES 7 and 9) which may be mounted on the underside of the support bar 22 3 and disposed to be actuated by the flange 22d of the drive bracket 212 as the latter moves along the lower course of the chain 1%.

In operation the above described transfer mechanism illustrated in FIGURES 8 through 14, inclusive, functions as follows. Generally stated, the transfer mechanism 159 operates to pick up a rack 177 from the shop conveyor and deposit it on a machine conveyor for loading a plating machine and after an indexing of the machine conveyor, serves to remove a fmished rack from the machine conveyor and deposit it on the shop conveyor. As pointed out above, in the transfer mechanism 15%, both of these functions are performed by a single loader-unloader unit, rather than by two separate units as in the embodiment illustrated in FIGURES l to 7, inclusive.

In one complete cycle of operation the cart 162 moves from a delay safety position indicated by the broken line showing 262 of the lift post end fitting 182, in FIGURE 9, to a second delay safety position indicated by the broken line showing 264 of another position of the lift post end fitting 182 and returns to the delay safety position 262. Describing the cycle of operation in more detail, the cart 162 starts from the delay safety position 26 2 in response to the actuation of a limit switch (not shown) on the shop conveyor by the arrival of a shop conveyor rack support in position for a rack carried thereby to be picked up by the transfer mechanism. It will be appreciated that during the initial movement of the transfer mechanism the drive bracket 212 is connected to the lower course of the chain 198 and moves toward the sprocket wheel 1%, and as it moves upwardly around the sprocket wheel, it raises the movable lift post 174- through the cooperation of the roller 24d with the fitting 182, causing the rack support arm 176 to follow a path indicated by the curve 248 in FIGURE 13, and lift a rack of unplated work from the shop conveyor. As the movement of the chain 198 continues, the drive bracket 212 moves the cart 16-2 toward the machine conveyor with the bracket 212 moving along the upper course of the chain 19$. When the bracket 212 reaches the sprocket wheel 1% it moves downwardly around the sprocket wheel 1% causing the rack support arm 176 to deposit the rack of unplated workpieces upon the machine conveyor.

The drive bracket 212 then moves along the lower course of the chain 1%, moving the empty cart 162 to the delay safety position 26d at which it is stopped by actuation of the limit switch 26%. The cart remains at this delay safety position while the machine conveyor operates to move the rack just delivered to the machine conveyor along the conveyor and move a rack of plated work into position to be removed from the machine conveyor by the transfer mechanism. The arrival in this position of the machine conveyor hook carrying a rack of plated Work actuates a limit switch (not shown) on the machine and starts the cart 162 from the delay safety position 26%- toward the sprocket wheel 1%. As the cart 1 32 approaches the machine, the drive bracket Z12 moves upwardly around the sprocket wheel 1% causing the rack support arm 176 to lift the rack of plated work from the machine conveyor. Upon continued movement of the chain 1% the cart 162 moves toward the shop conveyor with the drive bracket 212 moving along the upper course of the chain and as the bracket 212 passes around the sprocket wheel 1%, the rack support arms 176 deposit the rack of plated work on the shop conveyor hook. he chain 198 continues to move with the drive bracket 212 moving along the lower course of the chain and carrying the cart 162 to the delay safety position 252 in which it is stopped by actuation of the limit switch 258. in addition to stopping the chain 193 by stopping the iydraulic motor 212, the limit switch 258 signals the shop conveyor 24 to move the hook to which a rack of plated work has just been delivered, along the conveyor and to move into position another hook carrying a rack of unplated work. From the time that the cart 1 52 starts from the delay safety position 262 toward the shop conveyor until the cart returns to and is stopped at the delay safety position 2&2 by actuation of the limit switch 253, the shop conveyor is stationary. It is approciated, of course, that this may mean either that the shop conveyor runs intermittently, or that a type of shop conveyor is employed in which means are provided for maintaining a shop conveyor hool; stationary in pos "'on at the transfer mechanism while the shop conveyor in general continues to move. it will be appreciated that any suitable electric circuit and hydraulic system for providing the above described cycle of operation may be employed and accordin ly, it is not believed necessary to illustrate and describe in detail herein the electrical circuit and hydraulic system for providing this cycle of operations.

While the transfer mechanism illustrated in FIGURES 8 through 14, inclusive, employs a hydraulic motor 210, it is contemplated that if desired, a mechanical drive for the chain 198 may be provided. An embodiment of the present invention employing a mechanical drive is illustrated in FlGURE 16 which differs from the construction illustrated in FIGURES 8 through 14, inclusive, only in numerous modifications and changes may be made without departing from the spirit of the present invention.

What is cla med is:

l. A transfer mechanism for transferring work racks between two spaced stations comprising a frame, track means on said frame extending between the stations, a carriage movably mounted on said track means, guide means on said carriage, a column including rack-engaging means thereon mounted in said guide means for up and down movement relative to said carriage, roller means rotatably mounted adjacent to each end of said track means, a flexible drive element extending longitudinally of said track means and trained around said roller means, drive means for moving said drive element along said track means, and engaging means on and movable with said drive element disposed in driving engagement with said carriage for movement thereof between the stations in response to movement of said drive element and for engaging coacting means on said column for raising and lowering said column in response to the arcuate travel of said engaging means around said roller means.

2. A transfer mechanism for transferring work racks between two spaced stations comprising a frame, track means on said frame extending between the stations, a carriage movably mounted on said track 1.5121113, guide means on said carriage, a column including rack-engaging means thereon mounted in said guide means for up and down movement relative to said carriage, roller means rotatably mounted adjacent to each end of said track means for rotation about substantiallyhorizontal axes, a flexible drive element extending longitudinally of said track means and trained around said roller means, reversible drive means for moving said drive element along said track means, and engaging means on and movable with said drive element disposed in driving engagement with said carriage for movement thereof between the stations in response to movement of said drive element and for engaging coacting means on said colu A for raising and lowering said column and for halting reversing the direction or movement of said carriage in response to toe arcuate travel of said engaging means around said roller means.

3. A transfer mechanism for transferring worl: racks between two spaced stations compris a frame, track means on said frame extending between the stations, a carriage movably mounted on track means, a pair of transversel I spaced guide means on said car umn including racloengaging means thereon mounted in each of the pair of said guide means for up and down movement relative to said carriage, roller means rotatably mounted adjacent to each end or" said track means, a lexible drive element extending longitudinally of each side of said track means and trained around said roller means, reversible drive means for moving each said drive element in synchronization along said track means, and engaging means on and movable with each said drive element disposed in driving engagment with said carriage for movement thereof between the stations and for engaging coacting means on the lower portions of each said col: umn for raisin and lowering each said column and for halting and reversing the direction of travel of said carriage in response to the arcuate travel of said engaging means around said roller means.

4. A transfer mechanism for transferring work racks between two spaced stations comprising a frame, track means on said frame extending between the stations, a carriage movably mounted on said track means, guide means on said carriage, a column including rack-engaging means thereon mounted in said guide means for up and down movement relative to said carriage, a wheel rotatably mounted for rotation about a substantially horizontal axis adjacent to each end of said track means, a flexible drive element extending longitudinally of said track means between and trained around each said wheel, reversible drive means for moving said drive element along said track means, and means on and movable with said drive element including an arm having first engaging means thereon disposed in driving engagement with said carria e for movement thereof between the stations in response to longitudinal movement of said drive element and for halting and reversing the direction of travel of said carriage in response to the arcuate travel of said first engaging means around said wheel, said arm including second engaging means thereon for engaging coacting means on said column for raising and lowering said column in response to the arcuate travel of said second engaging means around said wheel.

5. A transfer mechanism for transferring work racks between two spaced sta ions comprising a frame, track "leans on said frame extending between the stations, a carriage movably mounted on said traclr means, guide means on said carriage, a column including rack-engaging means thereon mounted in said guide means for up and down movement relative to said carriage, a wheel rotatably mounted for rotation about a substantially hori zontal axis adjacent to each end of said track means, a flexible drive element extending longitudinally of said track means between and trained around each said wheel, reversible drive means for moving said drive element along said track means, means on and movable with said drive element comprising an arm including first engaging means thereon disposed in driving engagement with said carriage for movement thereof between tie stations and for halting and reversing the direction of travel of said carriage in response to the arcuate travel of said first engaging means around said wheel, said arm including second engaging means thereon for engaging coacting means on said column for raising and lowering said column in response to the arcuate travel of said second engaging means around said wheel, and supporting means extending longitudinally of said track means for supporting said arm during the longitudinal and arcuate travel thereof.

6. A transfer mechanism for transferring work racks between two spaced stations comprising a frame, track means on said frame extending between the stations, a carriage movably mounted on said track means, guide means on said carriage, a column including rack-engaging means thereon mounted in said guide means for up and down movement relative to said carriage, a sprocket ro tatably mounted on a horizontal adjacent to each end of said track means, a flexible drive chain extending longitudinally of said track means between and tra red around the sprockets, rever ible drive for moving said drive chain along said track means, an arm connected to and movable with said drive chain, means on said arm cooperating with a longitudinally extending supporting means for supporting said arm during its longitudinal travel and arcuate travel around said sprockets, first engaging means on and movable with said arm disposed in driving engagement with said carriage for movement thereof between the stations and for halting and reversing the direction of travel of said carriage in response to the arcuate travel of said drive chain around said sprockets, and second engaging means on said arm for engaging co acting means on said column for raising and lowering said column in response to the arcuate travel of said second engaging means around said sprockets.

7. A transfer mechanism for transferring work racks between two spaced stations comprising a frame, track means on said frame extending between the stations, a carriage movably mounted on said track means, guide means on said carriage, a column including rack-engaging means thereon mounted in said guide means for up and down movement relative to said carriage, a sprocket rotatably mounted on a horizontal axis adjacent to each end of said track means, a flexible drive chain extending longitudinally of said track means between and trained around the sprockets, reversible drive means for moving said drive chain along said track means, an arm connected to and movable with saiddrive chain, means on said arm cooperating with a longitudinally extending supporting means for supporting said arm during its longitudinal travel and arcuate travel around said sprockets, first engaging means on and movable with said arm disposed in driving engagement with said carriage for movement thereof between the stations and for halting and reversing the direction of travel of said carriage in response to the arcuate travel of said drive chain around said sprockets, second engaging means on said arm for engaging coacting means on said column for raising and lowering said column in response to the arcuate travel of said second engaging means around said sprockets, and sensing means operatively associated with said carriage and said stations for controlling the actuation of said reversible drive means for eifecting transfer of work racks between the stations.

References Cited in the file of this patent UNITED STATES PATENTS 2,806,577 Lang Sept. 17, 1957 2,807,349 Hauck et a1 Sept. 24, 1957 2,840,219 Mervyn et al. June 24, 1958 2,929,487 Lisowski et a1 Mar. 22, 1960 

1. A TRANSFER MECHANISM FOR TRANSFERRING WORK RACKS BETWEEN TWO SPACED STATIONS COMPRISING A FRAME, TRACK MEANS ON SAID FRAME EXTENDING BETWEEN THE STATIONS, A CARRIAGE MOVABLY MOUNTED ON SAID TRACK MEANS, GUIDE MEANS ON SAID CARRIAGE, A COLUMN INCLUDING RACK-ENGAGING MEANS THEREON MOUNTED IN SAID GUIDE MEANS FOR UP AND DOWN MOVEMENT RELATIVE TO SAID CARRIAGE, ROLLER MEANS ROTATABLY MOUNTED ADJACENT TO EACH END OF SAID TRACK MEANS, A FLEXIBLE DRIVE ELEMENT EXTENDING LONGITUDINALLY OF SAID TRACK MEANS AND TRAINED AROUND SAID ROLLER MEANS, DRIVE MEANS FOR MOVING SAID DRIVE ELEMENT ALONG SAID TRACK MEANS, AND ENGAGING MEANS ON AND MOVABLE WITH SAID DRIVE ELEMENT DISPOSED IN DRIVING ENGAGEMENT WITH SAID CARRIAGE FOR MOVEMENT THEREOF BETWEEN THE STATIONS 